WP7的独立存储

最近在做一个Windows phone 7上的客户端程序，较为简单，接触了WP7的一些东西，稍作笔记。WP7上的开发，是silverlght的又一次推广，所以入手容易，开发出来的效果也会很华丽。由Visual Studio、Expression Blend的强大支持，开发效率也会很高。本篇记叙下WP7的存储方式-独立存储。在参与的项目中，是用于保存用户添加的应用。

WP7 没有本地数据库API可以利用，提供的有XML、独立存储和云存储。Isolated Storage[独立存储]有两种方式在本地存储你的数据。第一是通过库中的键/值对，叫做IsolatedStorageSettings。第二是通过创建真实的文件和目录，叫做IsolatedStorageFile。

IsolatedStorageSettings:

using System.IO.IsolatedStorage;
//为程序获取一个虚拟的本地存储
IsolatedStorageFile fileStorage = IsolatedStorageFile.GetUserStoreForApplication();
//创建一个新的文件夹
fileStorage.CreateDirectory("textFiles");
/* 建立文件流，参数分别为：文件路径、打开模式、存储区。
* 打开模式有
* FileMode.Append-Opens the file if it exists and seeks to the end of the file, or creates a new file.
* FileMode.CreateNew-Specifies that the operating system should create a new file.
* FileMode.Truncate-Specifies that the operating system should open an existing file.
*      Once opened, the file should be truncated so that its size is zero bytes.
* FileMode.Create-Specifies that the operating system should create a new file. If the file already exists, it will be overwritten.
*      System.IO.FileMode.Create is equivalent to requesting that if the file does not exist, use System.IO.FileMode.CreateNew;
*      otherwise, use System.IO.FileMode.Truncate.
* FileMode.Open-Specifies that the operating system should open an existing file.
* FileMode.OpenOrCreate-Specifies that the operating system should open a file if it exists; otherwise, a new file should be created.
*
*/
IsolatedStorageFileStream isolatedFileStream =
new IsolatedStorageFileStream("textFiles//newText.txt", FileMode.OpenOrCreate, fileStorage);

//写入
StreamWriter fileWriter = new StreamWriter(isolatedFileStream);
//向文件中写出内容
fileWriter.WriteLine("write data");
//关闭StreamWriter.
fileWriter.Close();
//读取
StreamReader fileReader=new StreamReader(isolatedFileStream);
String str=fileReader.ReadLine();
fileReader.Close();
//判断存储区某文件是否存,参数是文件路径
fileStorage.FileExists("file path");

补充下：WP7的开发环境，下载Microsoft Visual Studio 2010 Express For Windows Phone，安装成功后，就自带有模拟器了。操作系统应该是Windows 7，在XP下，模拟器启动有问题。